French Systems, Inc.

David B Hindman

James S Paduchowski

Joseph D Lima

Norman E Wood

D Stephans Damtoft, Jr

Bruce A Wallace

David N Foster

Lawrence L Gerlach

A method of reducing the effects of fluctuating fluid pressure differential between the inlet and the outlet of a filtering unit operating in a system for filtering metal contaminants from a lubricating coolant and for recycling a constant volume flow of filtered lubricating coolant to a workpiece to be subsequently machined by pumping metal-contaminated lubricating coolant from a holding vessel to a filtering unit-modulator valve combination, monitoring the pressure or flow rate of filtered lubricating coolant downstream of the filtering unit-modulator valve combination, and operating the modulator valve in response to any changes in the downstream monitored flow parameter so as to maintain a predetermined constant fluid pressure differential across the filtering unit-modulator valve combination, thus compensating for fluctuations across the filtering unit during filtering operation, resulting in the maintenance of constant head pressure at the outlet of the pump, as well as for maintenance of a constant volume of flow of filtered lubricating coolant at a constant pressure to the workpiece to be machined.

Method for stabilizing the relationship between the filtering unit and a

A plurality of filter housing are arranged around a hollow hub section the interior of which is divided into an inlet chamber for receiving fluid under pressure to be filtered, an outlet chamber for receiving filtered fluid, and a backwash chamber that is connected to a waste line. Each filter housing contains an inverted, frustoconically shaped filter element having a closed lower end, and an open upper end connected to the outlet chamber of the hub section. Fluid that is to be filtered normally flows from the inlet chamber through a first series of valves to the lower ends of the filter housings, and then radially inwardly through the walls of the filter elements and out of the upper ends thereof and through a second series of valves to the outlet chamber. Because of its configuration, the pressure gradient across a respective filter element is substantially uniform throughout the entire axial length of the element, so that fluid is caused to flow through the entire useful surface of the element throughout its axial length. The lower ends of the filter housings can be selectively connected by a third series of valves with the backwash chamber. The first and third valves for each housing are interconnected, so that when a backwashing operation becomes necessary, the first valve is automatically closed at the time that the third valve opens, thereby causing a portion of the previously filtered fluid to flow in a reverse direction through the associated filter housing to the backwash chamber.

Backwashable filtering apparatus and novel filter element therefor

A plurality of open trenches or sluices is suspended from the underside of the forming floor of a glass factory to register with the lower, discharge ends of hot gob reject or cullet chutes. Each sluice is suspended with one end higher than the other, and with their lower, discharge ends communicating with one end of a large quenching tank, which is mounted on the floor beneath the forming floor. The tank contains a supply of cooling water, which is continuously pumped to the upper ends of the sluices, so that as hot gobs drop from the chutes into the sluices they are immersed in the cooling water and travel by gravity with the cooling water downwardly in the sluices to the quenching tank. A conveyor in the tank transports the cullet through the cooling water to a discharge point adjacent the opposite end of the tank. The bottom of each sluice is generally V-shaped in configuration so that frictional engagement of the hot cullet with opposite sides of a sluice is minimized.

Hot cullet handling apparatus

In a system having a fluid filter that is automatically backwashed each time the differential pressure thereacross reaches a predetermined value, the desired base rate at which the drop across the filter should increase during its initial filtering sequence (i.e., before backwash) is determined and stored in digital format in a process controller along with a preset maximum differential pressure at which backwash is set to occur. During use of the filter the actual rate of change of the pressure drop thereacross is monitored continuously and compared with the rate that is stored in the controller. Whenever the actual rate of change of the pressure drop across the filter differs from the base rate, which is the usual case, the present backwashing pressure is automatically adjusted--usually downwardly. This reduction continues until the actual drop across the filter finally reaches the adjusted value of the preset backwashing pressure, at which time backwashing of the filter is automatically commenced. In a preferred embodiment, the adjustment is based upon the time differential at a given instant between the actual filter time and the desired or base curve time, and the difference is used to reduce the preset pressure in accordance with the inverse of the base curve rate. In another embodiment the difference between the actual differential pressure across a filter and the desired differential pressure at any instant is determined and subtracted from the preset backwashing pressure.

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Rochester, NY, United States of America

David B Hindman